IBS is a gastrointestinal disorder characterized by chronic abdominal pain that can negatively impact quality of life and economic productivity. IBS can be classified into multiple subtypes based on the presence of abdominal pain and changes in stool frequency and consistency, including IBS with constipation (IBS-C), IBS with diarrhea (IBS-D), and IBS with alternating constipation and diarrhea (IBS-M). In the United States, IBS is estimated to affect 3 to 20% of the population, with a twice higher prevalence in women.
The standard for diagnosis of IBS has been criticized as unreliable and controversies exist as to the true etiology of the disease. Organic etiologies are rarely found, and IBS is generally diagnosed by excluding other causes for gastrointestinal symptoms. Diagnosis is difficult because of the functional nature of the syndrome and the symptom-based method of diagnosis as well as the similarity in symptoms between IBS and other diseases or disorders. Therefore, there is a need for better diagnostic and therapeutic tools for identifying and treating patients with IBS.